Akamai This document defines NEXT_HOP_MTU, an optional non-transitive BGP path attribute (type code TBD). It carries the IP MTU a speaker promises is acceptable for an NLRI across one network boundary. The speaker that receives the NLRI across that boundary may attach the attribute from the boundary interface MTU and advertise it on internal and external sessions. The intent is to communicate network MTU capability so that devices can use that information to improve the efficiency of their communications.